Shootas, Blood & Teef iz great fun. GET OUT DERE AN KRUMP SUM HUMIES YA GITZ. AAAAAAAAAAAAAAGH

Dicey Dungeons - Amazing music , light-weight fun but you still have to use your brain a little

Deeprock Galactic - ROCK AND STONE TO THE BONE

I heartily recommend trying Robocraft - it's free and a lot of fun :D